Control system for fluid motors



Filed Nov. a, 1945 June 21, 1949. A, MOLSON 2,474,187

CONTROL SYSTEM FOR FLUID MOTORS 3 Sheets-Sheet l June 21, A, M. OLSON CONTROLSYSTEM FOR FLUID MOTORS 3 Sheets-Sheet 2 Filed NOV. 2, 1945 3 Sheets-Sheet 3 A. M. OLSON CONTROL SYSTEM FOR FLUID MOTORS June 21, 1949.

Filed Nov. 2, 1945 6&9@

Patented `une 21, 1949 CONTROL SYSTEM FORLFDUIDQ MOTORS,

Albert M; Olson, Wauwat'osar Wis.,..

Ghain Belt Company,` Milwaukee,

poration of Wisconsin Application November 2, 1945,', Serial-No'. 626,290

(C1: (iD-97) 4 Claims.

The invention; relatesf to control systems for ni'd" motors; and` hasy for-one of its objects the provision of an improved system for the actuation and' controlof:` a plurality ofv hydraulic or similar motors which are to'- be operated in timed relationto one another;

Varions'kinds'of machinesincilude` two or more i'nstrun'rentalitiesv which are to be actuated in timed relation; to-one another, which f instrumentaliti'es` are of" a character w-l'iereoymotors ofthe reciprocating piston hydraulic type may beadvantageously employed. Asan illustrativel eX- ample'othis class-of'machine, reference'may be madeV to the; apparatus4` forl processing canned productsdisclosedA in prior U. S. Patent No. 2,348,440 granted May 9; 1944;' on'` an application edi'by Horaeel.. Smith; Jr., and Weld E. Confl'ey', Jr; Whileaswil'lappear more ful-ly below, the present invention is by noy means limited thereto, yetfor purposes of* disclosure its appli catonto the can feedingandA can transfer mech,- amsm'siof suchV a machiney hasbeen selectedfor iilustrationherev as affording atypical example of its use.

Briefly; theV apparatus of thesaid patent comprises aseries off power` driven. rolls disposed? in spaced parallel relation in. a tank or vat containing a fior-ving heat exchangemedium such as water; which rolls:v receive columns of axially alined cans' in the valleys between them, for rotation while-at' least-partially submergedin the heat exchange medium.- At determined intervals oscillating;` transfer members eiectl synchronized advance of" the several linesoi'cans to thev neXt succeedi'ngvalleys, whereby the cans are progressively'movedthrough-'the machin-sto a conveyer or other appropriate discharge dev-ice. Simulitaneouslywith reach advance of the lines of'cans within the machine, a fresh-batch of cans is suppli'edto the rst valleycf the roll series, the feed# ing mechanism including a' conveyer andan intermittently operablecan gripping device associated therewith 4for temporarily"arresting move.- 'ment' of a portion or tl'revlne of cans on the conveyerafterav determined number of cans has approach-edpositionfor-transfer to the roll series.

Whi'le in" the4 saidfpatentthe can grippingde-- vicey andthe oscillfatina'can transfer-members are shown as`v being` operated byfelectrical means, o themv may bef advantageouslyy operated 5,0 sectmn; and

assigfnory to Wis., a, conf memhersfarerelieyed ofthefweight of the cans,

as; the members, tra-vel4 more. or' less in. a downward,l directionnon their,` return strokes, such strolr'essmay beieffected withmaterially less pres:- sure inithegmotor thanx-is necessary for'the working strokes., It; istherefore a further objectof the invention; toi provide a system whereby at least; one: of. thepmotors mayA be;V operated atone pressmteron onegfoi: itsstrOKes andv atv a: dineren-t `pressurefonthe other stroke.

Thacan grippinagmechanism 'may bey and pret.- erabl-ysisv opera-teck at a.: pressure f lower than. that necess-ary-r tofelectfthe, working. strokes .of' the; can transfer mechanisrm in view-ofwhichthe-present system providesyiorl supplying fluidY to the circuit of trier- Cameri-prier motor-'1 fromthe'lower.' pressure notti-on of the .transfer'motorcircuit- @than objects; andradvantagesof the invention wilt apnearrasz the description proceeds.,

In' thefaccompanying dra-wings forming a part ofvtnis specicationz,

Figure; 1 is afsidefelevational view,- partly diargrammatic, of? aprocessine; machine ot the type disclosed in; the-said:4 prior Patent No. 2,348,440, itlnstratingi theyapplicationof oneform of the nresent hydraulic systemtothe :can gripping and can'. transfer'mechanisms of:V one deck of such machined;

Figs. v2, Sciandi are'diagrammaticviews. ofthe systerm and. mechanism, showingt successive phasesinzthe operation offthfe same;

Fiaeislawplarr View of the tim-ingmechanism for actiiatil'sigy the'control-valvesrof the two.' motor circuits, the housing therefor being shownW in sump or reservoir 54 through a pipe 55.

Fig. 6 is a side elevational view of the said timing mechanism, looking from the right of Fig. 5.

Referring to the said drawings more in detail, the processing apparatus shown in Fig. 1 comprises a vat or tank I which contains the heat exchange medium, and in which is mounted the series of can-supporting rolls and the oscillatory transfer bars mentioned above. The latter are intermittently operable from a rock shaft Il through linkage I2, the said shaft being provided with an actuating arm I3 operable by a double acting luid motor comprising a cylinder i4 having a piston I5 reciprocatable therein, and a piston rod i5 connected at I1 with said arm l5. Fluid under pressure is alternately supplied to and exhausted from 'the respective ends of the cylinder i4 through pipes I8 and I9 leading from control mechanism disposed Within a cabinet or housing 28 adjacent the machine.

The cans are supplied to the roll series by feeding mechanism located at the left hand end of the tank i0 (as viewed in Fig. 1) which mechanism has associated with it the intermittent can gripping mechanism referred to above, and here diagrammatically indicated at ZI. This device is operable by a double acting fluid motor comprising a cylinder 22 having a piston 23 reciprocatable therein, and a piston rod 24 which is lappropriately connected to the can gripping jaws; and fluid under pressure is alternately supplied :to and exhausted from the respective ends of the cylinder 22 through pipes 25 and 26 leading from `the control mechanism in housing 28.

Referring now more particularly to Figs. 5 and 6, the mechanism contained in the housing 2Il comprises a control valve 3l to which the pipes .I8 and I8 leading from the motor I4 are connected, and a control valve 32 to which the pipes 25 'and 25 leading from the motor 22 are connected. .Each o these valves has an actuating rod or stem 33 engageable by a follower arm 34, which arms are respectively operable by rotatable cams 35 and 35 carried by a cam shaft 31 which is -driven by a motor 39 through a reducing gear train 38. The cam 36 is here shown as being of an adjustable type having two segments 40 and 4I which may be adjusted arcuately relative to one another whereby to increase or decrease the length of the cam dwell and thus vary the length and/or timing of the gripping action as circumstances may require. The cam 35 of course may vbe of like construction, but for the purposes of the present apparatus a disc provided with an integral or rigid toe 42 will suffice.

As is best shown in Figs. 2, 3 and 4, the valve 3l is provided with an inlet port 45, a pair of exhaust ports 45 and 41, and a pair of motor ports 48 and 49, to the latter of which the pipes -I8 and I9 are respectively connected. These several valve ports are controlled by a recipro- `catable spool 50, which is movable in one direction by the cam actuated stern 33,

and in the opposite direction by fluid under pressure admitvted to a chamber 5l in the valve casing, as will appear more fully below. Fluid is supplied to the inlet port 45 through a pipe 52 leading from a gear pump 53 which draws its supply from a Abranch 5S of the pipe 52 contains a relief or safety valve 51 which drains back to the sump 54 through a -pipe 58, and which is set to relieve pressure in the line should it exceed, for example, 600 lbs. per

fsq. in.

The exhaust ports 46 and 41 of the valvel are connected by pipes 59 and 6I! with the sump or reservoir 54; and a branch 6I of pipe I8 contains a relief valve 62 which drains through a pipe 83 to the said sump, and which valve is set to maintain ya pressure of say not in excess of 125 lbs. per sq. in. in the line I8. A branch 65 of the pipe 55 is adapted to supply fluid at the higher, e. g. 600 lb., pressure to a pilot valve 66 which is disposed for actuation, either directly or indirectly, by the motor I4 through lost motion connections 81. In one position of this pilot valve (shown in Figs. 2 and 3) the supply line 55 is blocked off by the valve, while in another position of the said valve (shown in Fig. 4) its supply line 55 is connected to a pipe 69 leading to the chamber 5I of the control valve 3I. A relief line 15 connects the pipe 458 to the pipe I8, said relief line containing a relief valve 1I which may be set to limit the pressure exerted on the spindle 58 to say i5 lbs. per sq. in. when the pilot valve 85 opens communication between lines E5 and 89.

The control valve 32 for the motor 22 has an inlet port 15, a pair of exhaust ports 16 and 11, and a pair of motor ports 18 and 18, to which latter the pipes 25 and 2B are respectively connected. The inlet port 15 is supplied with fluid under say lbs. pressure through a pipe 80 leading from the pipe I8 and containing a check valve 8l; and the exhaust ports 15 and 11 of the motor control valve are connected by pipes 82 and 83 with the sump or reservoir 54` The several valve Vports are controlled by a reciprocatable Valve spool 84 movable in one direction by the cam actuated stem 33 and in the opposite direction by a compression spring 8-5.

In Fig. 2 the various parts are shown in the positions they occupy throughout a major portion of a cycle of the apparatus, during which the can gripping mechanism is operative to prevent cans from moving into tank I8, and the can transfer bars are in inoperative position below the several valleys of the roll series. At this time the pump 53 (which operates continuously) is supplying fluid at say 600 lbs. pressure through pipe 52 to the inlet port 45 of valve 3|, and the -Valve spool 58 has placed this port in communication with the motor port 48 so that fluid pressure is being exerted upon the top of piston I5 through the pipe I8, as indicated by the arrows. However, the relief valve 62 which is in communication with pipe I8 by the connection 6I is reducing the pressure in pipe I8 to say 125 lbs. per sq. in. so that uid reaching the upper part of motor cylinder I4 is under such reduced pressure. The valve spool 55 has also placed the exhaust port 45 in communication with the motor port 49 so that the line i9 leading from the lower portion of motor cylinder I4 is connected with exhaust line 59 leading to the sump 54. The motor piston I5 will thus be maintained in the lower position shown in Fig. 2.

Should the pressure of the uid in pipes 52 and 56 tend to exceed 600 lbs. per sq. in., the valve 51 will relieve such excess, venting the fluid to the sump through pipe 58.

In the meantime, fluid from pipe pressure, is passing through pipe I8, at 125 lbs. 88 and check -valve 8l to the inlet port 15 of valve 32 which ,is thus being exerted through pipe 26 upon the -lhausting fluid from until the pressure in chamber I equals that of the lower pressure side of the circuit. This increased pressure cannot be created until the spool 5l]i is returned and hence there is no danger of the cam follower putting undue pressure on the cam shaft prior to the passing of the toe d2 from engagement with the follower; but the moment the toe has passed the follower and the port 48 has been put into communication with the port d5, the pressure on the spool and its associated cam follower will build up until the pilot valve 68 is shifted to cut off supply of fluid to the line 69. Of course, no pressure can pass from the line i8 to the line 69 because the valve 1| checks all flow in this direction.

It will be noted that when the parts are in the Fig. 4 positions the line I8 of the transfer circuit (which normally supplies the fluid for the gripper circuit) is cut o from the supply line 52 leading from the pump, and is in communication with the sump 54 through exhaust pipes Sil and 59. At such time the pressure in line I8 will fall below the 125 lbs. per sq. in. normally maintained therein by the relief valve S2, which will tend to drainv fluid from the gripper circuit. However, the check valve 8l which is included in the feed line 80 of the gripper circuit will prevent any appreciable loss of pressure in this circuit while it is thus cut olf from its source of supply, and thereby prevent possible undesired movements of the gripping jaws which might interfere with proper feeding of the cans.

What is claimed is:

1. In a control system for a reciprocating fluid motor, a uid circuit for said motor; means for establishing differential fluid pressures in different portions of said circuit; a valve controlling said circuit, `movable between positions in which it successively connects the motor in the circuit for alternate movement of its working element in opposite directions at different pressures; connections between a higher pressure portion of said circuit and said control valve for supplying Imotive fluid to the latter; a pilot valve controlling said connections, operable by the motor as its working element approaches each terminus of movement to alternately supply and out olf motive fluid to said control valve to effect movement of the latter to one of its positions; means for reducing the effective pressure of the motive flui supplied to said control valve to move the same, and for securing a rapid build-up of pressure in the lower pressure portions of the fluid circuit to cause quick actuation of the motor element after the control valve has completed its movement, comprising relief connections between said motive fluid supply connections and the lower pressure portion of the circuit; and additional means for moving the control valve to its other position.

2. In a control system for a reciprocating fluid motor, a fluid circuit for said motor; means for establishing differential fluid pressures in different portions of said circuits; a Valve controlling said circuit, movable between two positions, in one of which it supplies fluid from a lower pressure portion of the circuit to one side of the working element of the motor to effect movement of said element in one direction, said valve in the other of its said positions supplying fluid :from a higher pressure portion of the circuit to the other side of said motor element while exthe first mentioned side thereof through said lower pressure portion of element in the opposite direction; means for moving said valve from its rst mentioned to its second mentioned position; connections between a higher pressure portion of the circuit and said control valve for supplying motive fluid to the latter to move it back to its first mentioned position; a pilot Valve controlling said motive fluid supply connections; means for actuating said pilot valve whereby to supply motive fluid to the control valve when the latter is in its second mentioned position; connections between said motive iluid supply connections and the lower pressure portion of the fluid circuit for venting part of the high pressure fluid from said supply connections to said lower pressure circuit portion, whereby to reduce the fluid pressure effective for moving the control valve and effect a rapid build-up of pressure in said lower pressure circuit portion when the control valve completes its movement; and a valve controlling said pressure reducing connections.

, 3. In a control system for a reciprocating fluid motor, a iiuid circuit having portions connected to the motor for alternate supply and exhaust of fluid to and from each side of the working element thereof; means for establishing differential fluid pressures in the respective circuit portions; a control valve in said circuit, movable between positions in which it effects alternate supply of fluid from said differential pressure portions of the circuit to said working element to move the latter in opposite directions at different pressures; connections between the higher pressure portion of the circuit and said control valve for supplying motive fluid to actuate the latter in one direction; means for moving said valve in the other direction; a pilot valve in said motive fluid supply connections; means for actuating said pilot valve to supply motive fluid to the control valve while the lower pressure portion of the circuit is exhausting fluid from the motor; relief connections between the motive fluid supply connections and said lower pressure portion of the circuit, for venting fluid from said supply connections to said lower pressure circuit portion, whereby to effect a rapid pressure build-up in the latter when the control valve completes its huid pressure induced movement; and a combined relief and check valve in said relief connections for securing a lowered uid pressure in a portion of said motive fluid supply connections for moving said control valve, said relief and check valve also acting to prevent reverse flow of fluid from the lower pressure portion of the motor circuit to said supply connections for the valve motive fluid when the pilot valve cuts off supply of fluid to the latter connections.

4. In a control system for a pair of intermittently operable fluid motors deriving their power from a single source, a fluid circuit for one of the motors; means for establishing differential fluid pressures in different portions of said circuit; a second fluid circuit, for the other of said motors, connected to and receiving its supply of fluid from one of the differential pressure portions of the first circuit; a valve in each of said circuits for supplying fluid therein to its motor to reciprocate the working elements thereof, the .valve in the rst circuit connecting the motor therein to one pressure portion during the forward stroke of its working element and to the other pressure portion during the return stroke ;of said element; means for actuating the valve in the first circuit in one direction by pressure vthe circuit, whereby to cause movement of said.15 from said first circuit; additional means for actuating said valve in the opposite direction; means for actuating the valve in the second circuit; and means for co-ordinating the action of the two last mentioned means.

ALBERT M. OLSON.

REFERENCES CITED The following references are of record in the 10 le of this patent:

Number Snader May 8, 1945 

